Simple, fast generation of RFC4122 UUIDs.

Heavily based on node-uuid by Robert Kieffer (I even copied this readme over and modified it.) Primarily becaue it works, well written, and so on.

Features:

• Generate RFC4122 version 1, version 4, or version 5 UUIDs
• Runs in dartvm and browsers.
• Cryptographically strong random number generation on all platforms
• • Defaults to non-crypto generator, see UuidUtil for cryptoRNG
• Annotated source code

1. Open a command line and cd to your projects root folder
2. In your pubspec, add an entry for dart-uuid to your dependencies (example below)
3. pub install
4. If you wish to run tests, go into packages/dart-uuid/ and run 'dart test/uuid_test.dart'

There are 2 options. Directly from git, or from pub.dartlang.org

pub.dartlang.org: (you can use 'any' instead of a version if you just want the latest always)

dependencies:
  uuid: 1.0.0

import 'package:uuid/uuid.dart';

var uuid = new Uuid();

Then create some ids ...

// Generate a v1 (time-based) id
uuid.v1(); // -> '6c84fb90-12c4-11e1-840d-7b25c5ee775a'

// Generate a v4 (random) id
uuid.v4(); // -> '110ec58a-a0f2-4ac4-8393-c866d813b8d1'

// Generate a v5 (namespace-name-sha1-based) id
uuid.v5(Uuid.NAMESPACE_URL, 'www.google.com'); // -> 'c74a196f-f19d-5ea9-bffd-a2742432fc9c'

Generate and return a RFC4122 v1 (timestamp-based) UUID.

• options - (Map) Optional uuid state to apply. Properties may include:

  • node - (List) Node id as List of 6 bytes (per 4.1.6). Default: Randomnly generated ID.
  • clockseq - (Number between 0 - 0x3fff) RFC clock sequence. Default: An internally maintained clockseq is used.
  • msecs - (Number) Time in milliseconds since unix Epoch. Default: The current time is used.
  • nsecs - (Number between 0-9999) additional time, in 100-nanosecond units. Ignored if msecs is unspecified. Default: internal uuid counter is used, as per 4.2.1.2.

• buffer - (List) Array or buffer where UUID bytes are to be written.

• offset - (Int) Starting index in buffer at which to begin writing.

Returns buffer, if specified, otherwise the string form of the UUID

Example: Generate string UUID with fully-specified options

uuid.v1(options: {
    'node': [0x01, 0x23, 0x45, 0x67, 0x89, 0xab],
    'clockSeq': 0x1234,
    'mSecs': new Date(2011,11,01).millisecondsSinceEpoch,
    'nSecs': 5678
})   // -> "1d6a6e2e-0457-11e1-9234-0123456789ab"

Example: In-place generation of two binary IDs

// Generate two ids in an array
var myBuffer = new List(32); // -> []
uuid.v1(buffer: myBuffer);
// -> [115, 189, 5, 128, 201, 91, 17, 225, 146, 52, 109, 0, 9, 0, 52, 128, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null]
uuid.v1(buffer: myBuffer, offset: 16);  
// -> [115, 189, 5, 128, 201, 91, 17, 225, 146, 52, 109, 0, 9, 0, 52, 128, 115, 189, 5, 129, 201, 91, 17, 225, 146, 52, 109, 0, 9, 0, 52, 128]

// Optionally use uuid.unparse() to get stringify the ids
uuid.unparse(buffer: myBuffer);    // -> '73bd0580-c95b-11e1-9234-6d0009003480'
uuid.unparse(buffer: myBuffer, offset: 16) // -> '73bd0581-c95b-11e1-9234-6d0009003480'

Generate and return a RFC4122 v4 UUID.

• options - (Map) Optional uuid state to apply. Properties may include:

  • random - (Number[16]) List of 16 numbers (0-255) to use in place of randomly generated values
  • rng - (Function) Random # generator to use. A Custom function that returns an list[16] of byte values or 1 of 2 provided.
  • namedArgs - (Map<Symbol, dynamic>) The arguments and values you want to pass to your function.
  • positionalArgs - (List) The positional arguments for your functions. if any.

• buffer - (List) Array or buffer where UUID bytes are to be written.

• offset - (Number) Starting index in buffer at which to begin writing.

Returns buffer, if specified, otherwise the string form of the UUID

Example: Generate string UUID with different RNG method

import 'package:uuid/uuid_util.dart';
uuid.v4(options: {
  'rng': UuidUtil.cryptoRNG
});
// -> "109156be-c4fb-41ea-b1b4-efe1671c5836"

Example: Generate string UUID with different RNG method and named parameters

import 'package:uuid/uuid_util.dart';
uuid.v4(options: {
  'rng': UuidUtil.mathRNG,
  'namedArgs': new Map.fromIterables([const Symbol('seed')],[1])
});
// -> "09a91894-e93f-4141-a3ec-82eb32f2a3ef"

Example: Generate string UUID with different RNG method and positional parameters

import 'package:uuid/uuid_util.dart';
uuid.v4(options: {
  'rng': UuidUtil.mathRNG,
  'positionalArgs': [1]
});
// -> "09a91894-e93f-4141-a3ec-82eb32f2a3ef"

Example: Generate string UUID with fully-specified options

uuid.v4(options: {
  'random': [
    0x10, 0x91, 0x56, 0xbe, 0xc4, 0xfb, 0xc1, 0xea,
    0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
  ]
});
// -> "109156be-c4fb-41ea-b1b4-efe1671c5836"

Example: Generate two IDs in a single buffer

var myBuffer = new List(32);
uuid.v4(buffer: myBuffer);
uuid.v4(buffer: myBuffer, offset: 16);

Generate and return a RFC4122 v5 UUID.

• options - (Map) Optional uuid state to apply. Properties may include:

  • randomNamespace - (Boolean) Default True. Returns if you want a v4 generated namespace (true) or NAMESPACE_NIL (false)

• buffer - (List) Array or buffer where UUID bytes are to be written.

• offset - (Number) Starting index in buffer at which to begin writing.

Returns buffer, if specified, otherwise the string form of the UUID

Example: Generate string UUID with fully-specified options

uuid.v5(Uuid.NAMESPACE_URL, 'www.google.com');
// -> "c74a196f-f19d-5ea9-bffd-a2742432fc9c"

Example: Generate two IDs in a single buffer

var myBuffer = new List(32);
uuid.v5(Uuid.NAMESPACE_URL, 'www.google.com', buffer: myBuffer);
uuid.v5(Uuid.NAMESPACE_URL, 'www.google.com', buffer: myBuffer, offset: 16);

Parse and unparse UUIDs

• id - (String) UUID(-like) string
• buffer - (List) Array or buffer where UUID bytes are to be written. Default: A new Array or Buffer is used
• offset - (Int | Number) Starting index in buffer at which to begin writing. Default: 0

Example parsing and unparsing a UUID string

var bytes = uuid.parse('797ff043-11eb-11e1-80d6-510998755d10'); // -> [121, 127, 240, 67, 17, 235, 17, 225, 128, 214, 81, 9, 152, 117, 93, 16]
var string = uuid.unparse(bytes); // -> '797ff043-11eb-11e1-80d6-510998755d10'

For more examples or usage, check my test implementations.

In dartvm

dart test\uuid_test.dart

In Browser

N/A as I have not used or tested this in the browser. But there are users of this library that do, and reported that it does infact work.

Its pretty quick, but no official benchmarking.

See CHANGELOG